|Posted on Friday, January 17, 2003 - 08:45 pm: ||
I have read a number of references to using and water and molasses at a 20:1 ratio to remove rust. An article I read stated that the decomposition of molasses resulted in a weak acetic acid solution and that is what removed the rust. My question is this: Why not use ordinary vinegar and water (2:1 or so) or buy a gallon jug of "Glacial Acetic Acid from an industrial supplier or a photographic supplier and dilute that (through trial and error)?
|Posted on Saturday, January 18, 2003 - 12:19 am: ||
Bob .....it is a bit of a mystery why or how the method works . I have never yet received a satisfactory explanation .Those that i hear range from an ion exchange being set up due the the alkyline nature of the mix to the other extrme of bacteria eating the oxide . I pased the method on to a friend in South Africa . He tried it but it did not work . He was advised by a chemist friend to add iron chelate to his mix ,i have not yet heard back as to the success or not of this mix . For me here in West Australia the method has been a great success.
|Posted on Sunday, January 19, 2003 - 07:10 pm: ||
The mollasses works by reduction which is basically the opposite of corrosion.
The most common type of iron corrosion is iron oxide(although in a marine environment there are other types) Iron oxide is a compound of iron and oxygen atoms.
Reduction or iron corrosion by reducing agents works by picking up oxygen atoms and leaving behind the iron atoms. There are a number of reducing agents and methods available to us, mollasses is one of them.
Unfortuntately they are not terribly efficient and typically result in the formation of different iron oxygen compounds. There is very little if any reduction back to pure iron.
Magentite is one such reduction compound that is fairly tough mechanically and will stop further corrosion to a degree.
Incidentally iron is manufactured by a very efficient form of reduction namely high temperatures(furnace) and a reducing environment.
A simplified explantion is:
Iron ore(which is basically lumps of very corroded iron) is heated to the point at which the iron will melt in a reducing atmosphere.
In one type of arrangement, the blast furnace, coke is used to heat the ore. The coke releases carbon monoxide(CO). Carbon monoxide is unstable and will in the presence of oxygen form carbon dioxide(CO2). The blast furnace removes the oxygen from the iron ore in this manner leaving behind iron.
Hope this answers your question. Peter I will find out about the chelated iron. I have a couple of theories on why this was recommended to you.
|Posted on Sunday, January 19, 2003 - 09:16 pm: ||
I probably did not answer this fully.
The cane sugar(saccharose) in the mollases is the reducing agent. Many sugars are. They are a carbohydrate(containing carbon,hydrogen and oxygen) and work in much the same way as the carbon monoxide above.
The vinegar and acetic are acids, that is they have a low PH. Molasses on the other hand has a PH of 9-11. The high PH "passivates" the metal meaning the corrosion process is essentially stopped.
I would not use acid to treat corrosion as it will attack the underlying sound metal. Reduction in a high PH environment will not.
|Posted on Monday, January 20, 2003 - 09:09 am: ||
Thanks Mark for that informative explanation .
|Posted on Tuesday, January 21, 2003 - 08:37 pm: ||
I have used Electrolysis to remove rust from rusty engine parts. It does a nice job without damaging your part.
This process has been discussed at lenth on Harrys old engine page.
I can post some links if you are interested
|Posted on Wednesday, January 22, 2003 - 03:17 pm: ||
Some links I posted on another thread some months ago.
Bill's electrolysis page
Sweet Sorghum "Rustbuster" http://www.syrupmakers.com/rust/
Glenn's Auto & Hobby page - derusting panels
Morris Registry of Victoria - dissolving rust
Hillman/Ron Beckett - Getting Rid of Rust
Rust & How to Remove It http://virtualindian.org/projrust.htm
Metal Web News - A Primer on Rust
Antique Auto Ranch - Rust Removal
Old Marine Engine - Removing Corrosion discussion topic
Gene Waugh's Tips on Rust Removal
Old Marine Engine - Clogged Water Jacket discussion topic
|Posted on Wednesday, August 25, 2004 - 05:16 pm: ||
I have an engine with flaking rust in the water passages. I am interested in ways to remove the scaling rust so that it does not block the cooling system of the engine once it is reassembled. The electrolysis method is very interesting, but I would need a large, strong container for that. Any suggestions? Thanks!
Post Number: 203
|Posted on Thursday, August 26, 2004 - 07:28 am: ||
Richard.....I am sorry to say that there is no easy way to remove that internal rust. I have had a cylinder soaking in molasses for about a year!It cleans the outside but the rust inside remains. It is tedious but i have found that a few different chisels probes etc tapping away the rust works . Also if you can rig up a length of multi strand wire [ such as a hand brake cable ] . Unravel one end and poke it into the water jacket using the inlet and out let connections , the water pump or even knock out the Welsh plugs[ you can replace these]. Connect the other end to you electric drill . You can realy work your way into all those innacessable areas . Some Diesel into the water jacket softens things up too.
|Posted on Thursday, December 16, 2004 - 07:09 pm: ||
The electrolisis method will work with water jackets in an engine, you need to use a length of stainless steel wire, run the wire through a plastic tube with holes drilled in increments of an inch or so, this will effectivly insulate the stainless steel wire from actualy touching the water jacket,now run the plastic tube with the stainless steel wire within, inside your water jacket. and attach this to the positive terminal of your battery or battery charger, then clamp the negative lead of your battery or charger to the engine casting, make sure your electrodes do not get submerged in your bath when you submerge your engine.
The stainless steel wire must be isolated enough from the insides of the engine to work, hence the plastic tubing.
Post Number: 142
|Posted on Thursday, December 16, 2004 - 08:31 pm: ||
Acetic acid should work inside jackets, particularly if it is pumped through continously. I've just acquired an ultrasonic cleaner the size of a washing machine, so we'll see what that can do with vinegar etc. The cavitation action occurs on every wet surface. Of course a process that reverses the rust is better than one that just removes it, all else being equal.
|Posted on Monday, October 30, 2006 - 12:51 pm: ||
I handle the facilities at our local YMCA and have a "wet stairwell" that was never set up with the best ventilation. The area gets wet as people get to and from our pools. I paint and scrape the rust, but need some advice on how to help slow the process of rust reappearing. Any thoughts?
Post Number: 178
|Posted on Monday, October 30, 2006 - 07:08 pm: ||
Probably an impossible task Jennifer with the sort of enviroment you mention. A steel staircase in this sort of situation should have been fabricated and surface treated to a particular code . So long since i have been personaly involved with such things but in essence it would need to be made to fully drain of water ,have non slip surfaces,have no areas where water could gather.The structure may have had to been fabricated in bolt together sections.
It would have required to be grit blasted and idealy hot dip galvanised.
What to do now....my advice would be to consult a firm of surface treaters [ industrial painters] for their advice on the latest surface treatments.Half measures will only prolong your task. Sorry there is no easy way out ,the enviroment your stairway is in is idea lfor corrosion.
Post Number: 3
|Posted on Monday, June 01, 2009 - 12:14 pm: ||
Since Were talking about Rust, I have a 40 hp. Evinrude with the drve shaft rusted in the crank shaft...Which is the best angle to apporch this....
Post Number: 3
|Posted on Tuesday, February 21, 2012 - 07:57 am: ||
Does anyone have any good ideas for stopping rust in cast iron marine engines that are directly cooled by sea water? I know about zinc anodes but some engines such as British Seagull outboard motors don't have any. In actual fact Seagull cylinder blocks often get their water jackets burst apart by rust. Some kind of vitreous enamel would be good but how could it be done?